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Re: [OpenCoarrays] RFC patch: Dependency/alias analysis wir same-image coarray access
- From: Alessandro Fanfarillo <alessandro dot fanfarillo at gmail dot com>
- To: Tobias Burnus <burnus at net-b dot de>
- Cc: gfortran <fortran at gcc dot gnu dot org>, opencoarrays at googlegroups dot com
- Date: Wed, 27 Aug 2014 15:17:00 -0600
- Subject: Re: [OpenCoarrays] RFC patch: Dependency/alias analysis wir same-image coarray access
- Authentication-results: sourceware.org; auth=none
- References: <53FD7DDA dot 4020808 at net-b dot de> <CAKT_9NUMbUFypmerL0aATRUhGZneFObFMtWpihTKegxQMPmqMw at mail dot gmail dot com> <53FE317F dot 4070803 at net-b dot de> <CAKT_9NX1pnxmzcnSbO8h-tfUOTVAN3V3yPU1qdO2Ge7aW2Xn6A at mail dot gmail dot com> <53FE434C dot 1080406 at net-b dot de>
On Wed, Aug 27, 2014 at 2:45 PM, Tobias Burnus <burnus@net-b.de> wrote:
> However, crucially is really the case (3), where the library has to generate
> a temporary array â independent whether the library handles overlapping
> memory access or not - and independently whether memmove is used or not.
> Prime example is - as I showed before - the case "a(10:2:-1)[1] = a(:)"
> where in a forward access to the memory, you have already overridden the
> memory location with a value before you read from it. (In that case, it
> helps what memmove does in that case: If you cannot walk forward, then walk
> backwards. But with multiple dimensions, one can create more complicated
> pattern.)
>
> Tobias
I see the problem here. Good point.
--
Alessandro Fanfarillo